It's a huge win. Larger than almost all the pre-primary polls indicated.

The exit polls from Fox News show that Romney won almost every single category of voters - whether they were young or old, whether they loved or hated the Tea Party. He won self-identified Protestants, Catholics and overwhelmingly won among Mormons. The only group of voters Romney didn't win was white Evangelicals. He lost those to Santorum 38% to 33%.

Suffice it to say, this state is an important one for Romney. It is a winner-take-all state, so Romney is netting 29 delegates.

Arizona, the state that gave the nation Barry Goldwater, is a bastion of modern Republicanism. In that state, the GOP wins people who want tough enforcement of immigration laws and border security, they win exurban 'values voters' and flinty old-line conservatives in huge numbers. And Mitt Romney is dominating that state tonight.

It's a sign that he can win among conservatives. At least that is what his team will be saying until Super Tuesday.